1. Field of the Invention
The invention relates to a chain link of a conveying chain, containing a base body with a first end region which comprises a first coupling section for the articulated connection to a coupling section of a first, adjacent chain link, and with a second end region which comprises a second coupling section for the articulated connection to a coupling section of a second, adjacent chain link. Moreover, the invention relates to a conveying chain which is formed of such chain links, as well as to a base body of such a chain link.
Conveying chains are applied in conveying technology, on which chains conveying members such as grippers or plate elements for conveying objects such as printed objects are for example attached. For this, the conveying chains are led along a revolving path by way of longitudinal guide devices of a conveying installation.
2. Description of Related Art
Such conveying chains as a rule are constructed of chain links connected to one another in an articulated manner. FR 2 232 497 for example describes a known embodiment of such a conveying chain. The conveying chain in this example consist of a plurality of chain links which in each case at a first end region comprise a first coupling section and at a second end region comprise a second coupling section. Both coupling sections contain openings arranged transversely to the longitudinal direction of the conveying chain. The second coupling section is designed in a fork-like manner. The chain links are connected to one another into a conveying chain, by way of the first coupling section being introduced between the fork lugs of the second coupling section of an adjacent chain link. A connection pivot is subsequently led through the opening on the first coupling section and on the fork tabs of the second coupling section and are connected to rotatably mounted runner rollers. The present design of the joint connection has the disadvantage that the chain links are pivotable only about one pivot axis formed by the connection pivot, i.e. in a plane perpendicularly to the connection pivot. A pivotability transversely to this, i.e. out of this plane, is not envisaged.
This limited pivotability of the chain links acts in a limiting manner on the design of the longitudinal guide device and the associated conveying path, along which the conveying chain is led. A limited deflection of the conveying chain out of the mentioned plane is only possible if the joint connection has play. Notwithstanding, such a design leads to an increased wear of the chain links, in particular in the region of the joint connections.
A ball joint link chain is suggested in the document DE 26 29 528, in order to avoid the outlined problem of the limited pivotability The pivotability out of the plane lying perpendicularly to the joint axis is achieved by a joint connection, with which the joint body of a first chain link which is designed in the form of a ball segment engages into a joint socket of an adjacent second chain link which is designed in an equal and opposite manner, and with this forms a type of ball-and-socket joint connection. The joint body is arranged in a fixed manner on a pivoting pivot which is arranged perpendicularly to the longitudinal direction of the chain link. In this manner, the chain links may likewise be pivoted in a plane which is aligned perpendicularly to the mentioned pivoting pin. Moreover, the joint connection also permits a pivot movement in a plane which is defined by the longitudinal direction of the connection elements and the pivoting pin axis. Moreover, the joint links can be rotated (twisted) with respect to one another about the longitudinal axis of the chain link.
The document EP 1 832 532 A2 also discloses a type of ball joint link chain, whose chain links form joint bearings. The joint bearings comprise two-part bearing housings which form a bearing socket for a bearing body. The bearing socket thereby encloses a joint body in a fixed manner. A partition plane which corresponds to a middle plane aligned perpendicularly to the housing axis is formed between the two bearing housing parts. Here too, the described joint connection additionally permits a movement perpendicular to the mentioned middle plane.
The embodiments of ball joint link chains described in the two documents DE 26 29 528 and EP 1 832 532 A2 however have the disadvantage that in each case components, in particular the joint socket and joint body, slide against one another with a pivoting movement. This over the longer term leads to an increased wear due to abrasion. An exchange of the ball joint link chains however requires much effort. Moreover, the joint socket and the joint body are greatly loaded due to the sometimes very high load peaks which occur for example as a result of an emergency stop.